Ecological Studies on the Vegetation of Swat District

Abstract

Ecological studies on the vegetation of Swat district were undertaken during 1989-93 to achieve the following objectives: To identify plant communities and their analytical and synthetic characteristics, to correlate different plant communities with soil and climatic conditions of the region, to study the impact of grazing and erosion on vegetation and identify threatened species.

The vegetation was sampled in plains by using Quadrat Method (10 X 10 m for trees and 2 X 2 m for herbs and shrubs) while in slopes by Line Transect Method. Three soil samples were collected from herbs and shrubs localities, at 24 cms depth while from coniferous/broad leaved forest at 36 - 48 cms depth. On the basis of data analysis, the 21 variable plant communities were established after importance value of three leading dominants, which are summarised in tabulated form (table 1). Table 1: - Plant communities in Swat District.

S.NO. LOCALITY/STAND COMMUNITIES ESTABLISHED ALTITUDE (Ft.) 1. Totalai graveyard Acacia modesta-Justiocia 1120 2. Gorghusti area (on way to Totalei) Acacia modesta-Olea ferruginea-Maytynus royleanus 1410 3. Ambela pass area Pinus roxburgii-Mallots phillipensis-Ziziphus 2200 4. Batora graveyard (Saidu Sharif) Olea ferruginea-Justicia adhahota-Achyranthus aspera 3250 5. Sangota graveyard Olea ferruginea-Cynodon dactylon-Amaranthus viridus 3300 6. Gokand area Pinus rox burgii-Mallotus phillipensis-Debregia sallisifolia 3200 7. Mataltan area Pinus wallichiana-Sorbaria tomentosa-Indigofera heterantha 7500 8. Janshey valley Picea smithiana-Abies pindrow 8620 9. Pir baba area Mallotus phillipensis-Celtis australis 2240 10. Thor warsak graveyard Olea ferruginea-Fumaria indicia Galium aparine 2240 11. Ushu area Quercus dilatate-Cedrus deodara 7024 12. Asala graveyard Olea ferruginea-Dicliptera roxburgiana 13. Mingora graveyard Olea ferruginea-Ailanthus altissima-Dodonea viscosa 3050 14. Matwani area (Deewan Baba) Olea ferruginea-Phonenix dactylifera-Poa annua 1900 15. Shanku village area (Madyan) Pinus wallichiana-Quercus dilatate-Rabdosia costata 6600 16. Kalam Band Rest House area Cedrus deodara Community 6730 17. Gabral area Pinus wallichiana-Cedrus deodara 8160 18. Durani area Pinus roxburgii-Mallotus phillipensis 3500 19. Marghazar palace area Pinus roxburghii-Rabdosia costata 4700 20. Miandam area Juglans regia-Poa nemoralis 5900 21. Karakar area Pinus roxburghii-Rubus fruiticosa 3005

The study shows 21 habitats in Swat District which are important from different practical aspect such as land capability classification of the area studied. The vegetation, climate and soil are interrelated. Mining for small extensive marble industries and emerald mine are serious threat not only to the original vegetation of the area but also to the whole wild life. Swat flora is primarily Himalayan and secondarily Russian Asian with of course some cosmopolitan elements. It was observed that Pinus wallichiana (blue pine) were suffering from mistletoes (Arceuthobium minutissimum) especially in upper Swat area.

Pinus gerardiana was recorded in open sunny places of Uthror,Janshey valley, Gabral etc. Cedrus deodara was found dominant near Band Rest House.Quercus baloot was also found dominant in the gorge above Bahrein and in Ushu areas. There were few Fraxinus xanthoxyloides and F. excelsior in Ushu area. Quercus dilatata was also recorded in small quantity in Kalam area. The established plant communities were correlated with soil and climatic factors. The vegetation in some areas of Swat district has been considerably damaged during the last few years by local inhabitants and Afghan refugees who are living in the camps like Coga Afghan Refugees Camp in Lower Swat and in the border regions. These people use whatever comes in their way whether trees, shrubs or herbs for meeting their shelter/fuel requirement as well as fodder for their livestock, resulted in accelerated soil erosion of the hilly torrent and tributaries of the rivers like Ushu, Uthror, Swat etc., especially in the Upper and Lower Swat areas.

Of the 1473 taxa of flowering plants and 55 ferns and fern allies. (Stewart, 1967) 34 plants are seriously threatened. Our present list includes plants which are either already very scarce in distribution or are being seriously threatened by the destructive forces of over-grazing, deforestation, soil erosion and rapid colonization. Some taxa have been collected from one locality only, and are thus quite rare in distribution and are considered to be vulnerable to the hazards of environmental degradation. Some endemic, flora of Swat is threatened. The matter, nevertheless, calls for a concerted action for the conservation of natural heritage of area. The effect of man and animals in Oak forest (Quercus incana, Q. baloot, Q. dilatata & Q. semicarpifolia) is well marked, since the oaks are heavily cut, lopped and suffer greatly at the hands of man and animals. It is interesting to note that east from Kalam past Ushu to the first glacier on Mt. Mankial.

According to the data on impact of soil on various plant communities, it was observed that most of the plant communities were common in different types of habitat and soil conditions. It has not been found possible to associate them with one particular type of soil. However, some of the plant communities confined to one or two types of soil conditions.

It has also been observed that different types of soil run into each other through different gradations. Variation in the vegetation between different soil types /habitats and within particular soil may be attributed to the variation in water availability and the degree of exposure to sun and other microclimatic differences.

The soil is normally alkaline, pH ranges from 7.30 - 8.84. Soil type is loamy sand in stands/ areas like Totalei, Ghoghushti etc. Its xerophytic characteristic i.e., small leaves, deep and rapid growing root system and ability to survive in variable soil characteristics have made Acacia modesta adaptable to grow in diverse type of habitats.

It was observed that old graveyards indicate the remnants of original vegetation of Acacia modest with Olea ferruginea because there is a taboo against cutting graveyard trees and as each village has its cemetery. In the major areas of Buner sub-division and Middle Swat like Saidu-Sharif, Mingora, Sangota due to heavy grazing the climax type have been degraded to scrub and presumed tree stratum has either been completely eliminated or only by an occasional survivor. The heavy grazing has consequently pushed the unplateale species in to dominance in the sites of Karakar, Gokand, Marghazar, Totalei, Changlei etc only these species can survive in such condition like Calotropis procera, Acacia modesta, Gymnosporea royleana, Carrisa oppaca, Ziziphus species, Periploca aphylla in subtropical thorn forest and in Chir-pine sub-tropical forest these species can survive like Berberis lycium, lndigofera heterantha etc.

In higher altitude vegetation is influenced by climatic factors such as rainfall, humidity, ultra-violet radiation, temperature and winter precipitousness of slope. The highest trees were white birches. Near Kalam in Janshey valley the last trees were Q. semicarpifolia (Brown oak),, an oak with a spotty distribution. In higher regions Quercus dilatata and Q. semicarpifolia etc, shifting cultivation & establishment of temporary hutments for cattle have led to the destruction of the vegetation, with the result that on clearing the floor is covered with luxuriant herbaceous vegetation in Desan and Janshey.

Natural vegetation of the lower montane belt mainly consists of Pinus roxbughii forest, have been depleted due to human impact. Subtropical temperate sclerophyllous forest communities (Acacia modesta - Olea ferruginea- Quercus balloot) occur, mostly transformed into degradation stages. Higher up temperate coniferous forest of Picea smithiana and prevalent interspersed with dicidous tree of the genera, Acer, Prunus, Aesculus, Alnus, Diospyrus etc. on shady slopes in the sub alpine belt the natural vegetation gives way to Betula utilis forest- Salix krummholz, whereas on sunny slopes the conifeous forests are followed by Juniperous. Above the tree line alpine dwarf scrub heath and meadows occur.

The present studies were carried out for the first time to record present accurate picture of the vegetation and to know the basic ecological feature of the area before the entire ecosystem is disturbed and its wildlife reaches the point of extinction. Hopefully the results thus obtained can work as guidelines for stepping up a balanced future development of the area.

Quercus dilatata and Q. semicarpifolia etc, shifting cultivation & establishment of temporary hutments for cattle have led to the destruction of the vegetation, with the result that on clearing the floor is covered with luxuriant herbaceous vegetation in Desan and Janshey.

Natural vegetation of the lower montane belt mainly consists of Pinus roxbughii forest, have been depleted due to human impact. Subtropical temperate sclerophyllous forest communities (Acacia modesta - Olea ferruginea- Ouercus balloot) occur, mostly transformed into degradation stages. Higher up temperate coniferous forest of Picea smithiana and prevalent interspersed with dicidous tree of the genera. Acer, Prunus, Aesculus, Alnus, Diospyrus etc. on shady slopes in the sub alpine belt the natural vegetation gives way to Betula utilis forest- Salix krumnholz, where as on sunny slopes the coniferous forests are followed by Juniperous. Above the tree line alpine dwarf scrub heath and meadows occur. The present studies were carried out for the first time to record present accurate picture of the vegetation and to know the basic ecological feature of the area before the entire ecosystem is disturbed and its wildlife reaches the point of extinction. Hopefully the results thus obtained can work as guidelines for stepping up a balanced future development of the area.